Advertisements improvements

[Maxtor]

There should be some additional features for IPS advertisements such as:

1) Show expiration date for banners to customers.

2) Show an advertising banner when spot is free and replace it only if a user buys the banner spot with his advertising banner.

3) Option to preorder banner before expiration date for higher price.

4) more advertising spots and options.

[Adam_S]

I'd also like to add

5)  The ability for a buyer to change their banner themselves by uploading a replacement one